/*
 * =============================================================
 *
 *        Project:  apue
 *
 *       Filename:  f4_22.c
 *
 *         Editor:  vim :set et ts=2 sts=2 sw=2
 *
 *         Author:  Martin Y. Yang , yang@libpix.org
 *
 *    Description:  
 *
 * =============================================================
 */

/**
 * @file
 * @brief Figure 4.22 Recursively descend a directory hierarchy, counting file types
 */

#include "apue.h"
#include <dirent.h>
#include <limits.h>

typedef int Myfunc(const char *, const struct stat *, int);
static Myfunc myfunc;
static int myftw(char *, Myfunc *);
static int dopath(Myfunc *);

static long nreg, ndir, nblk, nchr, nfifo, nslink, nsock, ntot;

int ftw4_main(int argc, char *argv[])
{
  int ret;
  if (argc != 2)
    err_quit("usage: apue 4.22 <starting-pathname>");
  ret = myftw(argv[1], myfunc);

  ntot = nreg + ndir + nblk + nchr + nfifo + nslink + nsock;

  if (ntot == 0)
    ntot = 1;
  printf("regular files  = %7ld, %5.2f %%\n", nreg, nreg*100.0/ntot);
  printf("directories    = %7ld, %5.2f %%\n", ndir, ndir*100.0/ntot);
  printf("block special  = %7ld, %5.2f %%\n", nblk, nblk*100.0/ntot);
  printf("char special   = %7ld, %5.2f %%\n", nchr, nchr*100.0/ntot);
  printf("FIFOS          = %7ld, %5.2f %%\n", nfifo, nfifo*100.0/ntot);
  printf("symbolic links = %7ld, %5.2f %%\n", nslink, nslink*100.0/ntot);
  printf("sockets        = %7ld, %5.2f %%\n", nsock, nsock *100.0/ntot);

  exit(ret);
}

#define FTW_F 1
#define FTW_D 2
#define FTW_DNR 3
#define FTW_NS 4

static char *fullpath;

static int myftw(char *pathname, Myfunc *func)
{
  int len;
  fullpath = path_alloc(&len);

  strncpy(fullpath, pathname, len);
  fullpath[len-1] = 0;

  return(dopath(func));
}

static int dopath(Myfunc* func)
{
  struct stat statbuf;
  struct dirent *dirp;
  DIR *dp;
  int ret;
  char *ptr;

  if (lstat(fullpath, &statbuf) < 0)
    return func(fullpath, &statbuf, FTW_NS);

  if (S_ISDIR(statbuf.st_mode) == 0)
    return func(fullpath, &statbuf, FTW_F);

  /*
   * It's a directory. First call func() for the directory,
   * then process each filename in the directory.
   */
  if ((ret = func(fullpath, &statbuf, FTW_D)) != 0)
    return ret;

  ptr = fullpath + strlen(fullpath);
  *ptr++ = '/';
  *ptr = 0;

  if ((dp = opendir(fullpath)) == NULL)
    return func(fullpath, &statbuf, FTW_DNR);

  while ((dirp = readdir(dp)) != NULL) {
    if (strcmp(dirp->d_name, ".") == 0 ||
        strcmp(dirp->d_name, "..") == 0 )
          continue;
    strcpy(ptr, dirp->d_name);

    if((ret = dopath(func)) != 0)
      break;
  }
  ptr[-1] = 0;

  if (closedir(dp) < 0)
    err_ret("can't close directory %s", fullpath);
  return ret;
}

static int myfunc(const char *pathname, const struct stat *statptr, int type)
{
  switch (type) {
    case FTW_F:
      switch (statptr->st_mode & S_IFMT) {
        case S_IFREG: nreg++; break;
        case S_IFBLK: nblk++; break;
        case S_IFCHR: nchr++; break;
        case S_IFIFO: nfifo++; break;
        case S_IFLNK: nslink++; break;
        case S_IFSOCK: nsock++; break;
        case S_IFDIR: 
            err_dump("for S_IFDIR for %s", pathname);
      }
      break;
    case FTW_D:
      ndir++;
      break;
    case FTW_DNR:
      err_ret("can't read directory %s", pathname);
      break;
    case FTW_NS:
      err_ret("stat error for %s", pathname);
      break;
    default:
      err_dump("unknown type %d for pathname %s", type, pathname);
  }
  return 0;
}



